Productive people create productivity tools to make them more productive. Unproductive people think those same productivity tools will magically make them work better, but most of the problem lies in a lack of self-discipline, rather than lack of a magic tool.
I have my homegrown software based on Autofocus, which as a system is enough for 95% of senior engineers. However, I've just added some additional responsibilities that draw me from a "maker" schedule more and more. My problem isn't that I'm not productive in terms of an hours worked perspective -- my problem is that I need help focusing on the right things in the face of competing requests.
GTD, for example, is fantastic for that. It's terrible for the average developer. Most developers can rely on their bug tracking software as their "productivity software" with a simple todo list and calendar reminders for due dates of non-code requirements. (e.g. HR paperwork)
I don't need a magic tool to make me productive; I need a tool to function as a priority queue. If you want a tool to make you productive, you're looking at the wrong tool.